One Heart
by CloverRin
Summary: Kagamine Rin is a girl with a big heart, who's in love with her best friend, Kagamine Len. When she gets a disease and is sick for a while, her whole life starts to change, all because of one little thing. As her sickness worsens, so does her heart. Rin x Len, with character death.
1. Prologue

Some things happen in a heartbeat.

FLASH. In a split second, everything changes. Some things change even when you thought they'd stay the same forever.

One day, you're outside, a wonderful feeling inside of you.

The next day…

BOOM. Everything has changed, and nothing is the same as before. Nothing can be the same forever, as much as you wish it could be.

This is why we have tears. This is why they fall in crystal droplets, small patters sounding as they delicately slide off of your cheeks. This is why they're here for us.

This is why I suffered…because the tears fell so much, twisting my stomach in so many different directions.

Every single thing on Earth has a center.

For a person, it's their kokoro, or their heart.

There is a kokoro in every person. Every person has a kokoro. Kokoros break. Kokoros glow. Kokoros suffer. Kokoros shine.

Kokoros die.

_Crystal tears will fall_, a voice inside my head would call. _It's fate. There's no escaping that. They will fall and shimmer as they touch the ground softly by your feet. Choose your path wisely. Keep your kokoro._

This was all a voice inside my head, a measly voice that could be hallucination from all of the hurt coming to me. Did I listen?

No.

This is probably why my heart, my kokoro, has suffered for me, holding in the pain, the grief, the torture. I tried to keep my kokoro perfect, for some day it would spring into happiness once true love touched me lightly, calling for me.

Then, in a heartbeat, it all changed…disappeared…

The tears fell heavily. The pain grew bigger as each sorrowful day passed. My kokoro hurt more as the days went on, and it grew harder to sustain a happy kokoro…a happy mind…a happy life…

Twisting…turning…my whole life was dissolving before my eyes.

The voice had helped me, reached out a hand in kindness towards me. But I didn't grab it back.

I just ignored it.

I DESTROYED it.

But as the tears fell, my heart cleared out each hurtful word, phrase, memory, easing out of my soul. And that is why we need tears, why tears exist, why they're here for us…

…to clear our kokoros…

I can't say this shouldn't have happened to me. Life will go on…life will be different for everyone. And heartbreaks will occur at any given moment. It's part of life. If this is my fate, so be it.

But some things happen in a heartbeat.

Flash…

And everything changes.

Remember this…

Before it's too late.

-Kagamine Rin, the girl who lost her one heart.


	2. Snow

**Author's Notes-**

** Hi everyone! Thanks for coming to read Chapter 1 if you liked the prologue! PLEASE READ AND REVIEW! Your reviews help me to write more, so please keep doing it! Here's Chapter 1! Please Enjoy! (If you have any questions or ideas for later, please tell me and maybe I can add it into the story ;))**

The light moonlight peeked out of the dark clouds as Rin ran back to the Vocaloid house. A heavy snow was falling, and it was getting super dark. Well, it was almost 9:00. She sniffed as her nose started to run. The coldness had frozen her, and all she had to warm herself was a light coat and a scarf around her neck. She pulled her scarf over her red nose and sighed as her legs shivered.

"I can't believe Miku made me wear a SKIRT to dinner today," Rin mumbled, her legs freezing off as well. All she had on her legs were her knee-high socks and the short skirt to cover…practically nothing. Skirts were stupid. It wasn't even worth the 10 bucks Miku offered to give her if she DID wear one.

Rin had totally had enough of Miku today. She had even forgotten to drive her back home after dinner. Now it was snowing, and Rin had to walk back in a skirt. A SKIRT people!

Rin sniffed again as she FINALLY saw the Vocaloid house. Her head was starting to get a little dizzy, so she was glad to feel a blast of warm air touching her frozen body as she opened the big doors. "I'm home…finally," Rin said as she tiredly walked into the house.

"Rin! Are you okay?" Rin heard a familiar voice call as a certain special blonde ran up to her. Yes, it was her best friend, Kagamine Len.

Rin nodded. "Y-yeah, Miku just forgot me so I had to walk home in the freezing cold and snow…and darkness…" Rin held her head and sniffed again as her nose started to run once more.

Len picked Rin up bridal style before she collapsed onto the floor. "Rin, you look horrible!"

"Aren't you nice," Rin mumbled. She hated being picked up this was, even if it was from her best friend.

No, more like, her ultimate crush.

Ever since Rin and Len were little, they had been best friends. As the years went on, Rin thought of Len much more than a friend…although she knew Len would never think of her in that way.

Usually, Rin would hate being held bridal style, but she felt so dizzy and awful that she let Len hold her that way…not to mention it felt kind of good.

Len and Rin still shared a room because all of the Vocaloids were too lazy to give them each separate rooms. Rin didn't care all that much, but then again, wouldn't it be so awkward to sleep in the same room as your best friend/your crush? Yeah. Now you know how I feel.

Len sat me down on his bed. I sat up. "L-Len, this is your bed, not mine," Rin said.

Len nodded. "I know. You're sleeping with me tonight, in my bed, so I can keep an eye on you. And we're going to bed early so you can get some sleep."

A huge blush streaked across Rin's cheeks. "W-what?" Rin asked, but Len was already holding her close. Rin was too tired and too comfortable to complain, so not even bothering to change out of her skirt, socks, and shirt, (she had already taken off her jacket and her scarf), she fell asleep in her best friends' arms.

-The next morning, Len POV-

I woke up, remembering that Rin was in my arms. I smiled as I saw her sleeping soundly, her face cute as an angel. Her nose was still red, and she was feeling hotter than before. I felt her forehead and my hand almost started to burn.

"Oh god," I whispered, slowly getting out of my bed so I didn't wake Rin up. Running downstairs, I called, "Luka! Miku! HELP! IT'S RIN!"

Luka was the first one to come over. "Rin? Where? What happened? Is she okay?" At the tone of my voice, I think I made her a little too nervous…

"W-well, she was sleeping in my bed because she wasn't feeling well yesterday. Then, I woke up, and her forehead almost burned my hand. Plus, her nose had been running a lot. Does she have a cold AND a fever?"

Luka ran up to our room, and I saw Miku follow me soon after. She asked me a whole lot more questions about Rin than Luka had.

Luka opened the door, making Rin wake up with a start. Her eyes looked extremely tired and her face was red.

"Wha…?" Rin asked as Luka jumped onto the bed she felt Rin's forehead and her eyes widened. "That is one SERIOUS fever!" She cried.

I gulped. NOT. GOOD.

**Author's Notes-**

** Hi everyone! I know, you must be thinking, "What's up with all of Clover's short chapters? They're usually longer!"**

** Sorry! They'll be longer as the story goes on. I just needed to add some suspense ^ ^**

** Anyways, I'm SO Sorry for the slow updates lately! I don't know what's up with me. I usually make loads of new updates fast, but since I haven't, today I will work extra hard to make it up to you all! (I'm going to work on Chapter 2 right now, after I post Chapter 1)**

** Thank you so much to everyone who is reading! It means so much to me…**


	3. The First Heartbreak

-Rin POV-

"Huh? Fever?" I gulped. My head was still hurting, and my nose was still running. I sniffed. This was NOT good. I had school tomorrow! I couldn't miss school…and Luka said I had a major fever.

"Get the medicine, Miku!" Luka told her. Miku nodded and ran downstairs. My head throbbed as she banged her feet against the steps in a hurry. Click, clack, click, and clack.

"Oh…" I moaned. I lay my head back on Len's pillow as blackness started to overcome me. Len's shouting voice became fuzzy as I became unconscious…

"Wh…where am I…?" I asked as I woke up. My head felt slightly less dizzy, but I was still feeling hot and cold. Shivering and sniffing, I felt Len's sheets being pulled over me.

"You're in your room, silly." Len's voice. I looked up at him.

"H-How long was I asleep?" I asked, lifting my tired arm to rub my tired eye.

"Um…about 5 hours." My eyes widened.

"Don't worry about it. Of course I would've waited for you to awaken." I saw Len smile, my vision slightly blurry. "But you have to take this medicine." He held out a bottle.

"NO! NO WAY WILL I EVER HAVE THAT HORRIBLE STUFF!" I screamed, suddenly getting loads of energy back. "IT'S EVIL!"

"Rin please, it will make you feel better!" Len said. He climbed onto his bed with me to try and calm me down.

"NO!" I tried to scramble away from Len but he pinned me down, putting us in an awkward position. I gasped. Len's face was as red as mine.

"Rin, I have to give you this medicine to make you feel better!" Len said, still blushing.

I shook my head, pretending to pass out again. "I…don't…w…"

"Rin! Wake up!" Len tapped me. Then, I fell asleep for real.

When I woke up, I found myself in my own bed. "Huh?" I said. Len wasn't here, and I had gotten out of taking the medicine. "Yes! Ha!"

When I sat up, my head hurt more than usual. I shook it off. "I'm probably just worn out…"

Going into the bathroom, I noticed the time. "10:30? Man, I slept for a LONG time! Everyone must be at school…"

I gulped. I wasn't at school with Len. This. Was. Bad.

Last time I had had to stay home from school, Neru, my enemy, had apparently asked Len out on a date because I wasn't there. Miku had texted me during class and my heart twisted so badly I thought I would burst.

I was relieved when Len had come home and told me he didn't say yes. But, that was 5 years ago.

What would happen if she tried again and Len said YES!?

_'Oh, come on, Rin!'_ My inner self said. _'Len wouldn't go out with such a self centered JERK! You know him better than anyone, maybe even better than you know yourself. Stop worrying.'_

I nodded. I hoped I was right.

The time seemed to slow down a few thousand hours just for me. I was bored to DEATH, not to mention when I actually did go into the bathroom I saw that my face was practically pure white. I couldn't believe how pale being sick could make you.

Finally, I got a text from Miku. _'Don't worry Rin, we're coming come!'_

I sighed in relief. Miku hasn't sent me anything about Neru. _Maybe everything's fine. I shouldn't be worrying._

When the doorbell rang, I ran downstairs, happy to know that Neru wouldn't be a problem. But when I opened the door-

"NERU?!" I cried. "What're YOU doing here?"

"I could be asking you the same question." The blonde smirked. My heart twisted as I saw who was next to her.

Len. My best friend and my crush. His arm intertwined with Neru's arm. He looked at my horrified, sad face.

"Um…hey Rin," Len smiled nervously. I was still in shock.

"B-But, L-Len," My eyes watered up in tears. "H-How…"

"Look, Rin, I can expla-"

"Explain what?" Neru put on her best sad face. "Y-You don't L-love m-me?"

Len sweat dropped. "N-no, sweetie, that's not it…"

I gulped. How could this be? It COULDN'T be! I looked at Miku who was standing behind the other two.

"Oh, um, hey Rin," she smiled. I could tell she felt horrible for me.

"Look, Rin, let me just-"

I cut Len off by running away, tears streaming down my face. I burst open the doors and ran out, the cold pinching at my clothes. I hadn't even bothered to put on my coat or my scarf.

Faster and faster my feel ran. I could tell Len was trying to catch up to me, but I was faster than him. Not only that, but I heard him stop, and a voice said;

"Forget about her. You have me now. Unless you don't love me…"

That did it. That just cut across the edge. Len didn't even bother to chase after me with that…that…that THING with him! More tears streamed out of my eyes, being frozen as they were caught by the cold. I sniffed again, my vision becoming blurry once more. I could tell that I was getting worse, but I didn't even care anymore. Neru? Over me? Just…how?

I, Kagamine Rin, passed out on the side of the street.


	4. Confusion

**-Rin's POV-**

I woke up, my vision fuzzy at first. I looked around. _My room…_

I almost wanted to growl at the first thing I saw. Len's bed. Len…the person that I now hate…the person that WAS my best friend. Not anymore.

Not even a chance.

My head throbbed. _I wonder who brought me back…_

My head felt like it was about to explode. I groaned, laying back in my bed until a head popped out from behind the door.

It even hurt to look up. "M-Miku…?" I said weakly. I could tell I was getting worse by hearing the sound of my own voice.

Miku walked in and sat down at the foot of my bed. "Hey, Rin." She gave me a weak smile.

"M-Miku…who brought m-me back…" I could almost hear her saying that it was Len.

"Luka and I ran out as soon as you passed out to get you," Miku replied, knowing I wanted to hear Len's name.

"L-Len didn't even try t-to get m-me…?" I stuttered, my eyes filling with tears. I tried to sit up, but a horrible pain shot through me. I receded back down, moaning as silent tears ran down my cheeks.

Miku sighed. "I'm so sorry…" she looked down.

"It's okay," I said. I shivered as a sudden chill ran through me, and then I started to sweat. It's hard being hot and cold at the same time.

"I-I just…" It even hurt to talk. I was in such a horrible condition.

"I-I's like to b-be left alone f-for a bit," I sniffed, crying weakly into my pillow.

**-Miku's POV-**

I nodded and left slowly, rubbing Rin's back for a moment. I walked back downstairs and sighed. Rin and I were extremely close friends, so a lot of times, I could feel her pain.

As I stepped into the kitchen to grab a leek, I stopped, hearing voices. Peeking into the living room, I gasped.

Len and Neru were together. Man, they have some nerve to sit together in our house with a sick, broken-hearted Rin.

I hid behind the couch when they weren't looking so I could listen in on their conversation.

"Len, do you love me?"

Neru's voice sickened me. I wanted to barf as Le said his next words.

"Of course I do. Why would you think such a thing?"

_ I'm going to kill you later, Len,_ I thought, making a fist.

"W-Well," Neru started, trying to sound innocent, "It's just that, you're always with Rin, and…"

_What? She got cut off…and what's that noise? Miku _asked. She peeked over the couch, her eyes widened.

_ Had Len kissed Neru?!_

"LEN!" I suddenly screamed, totally forgetting I was supposed to be hiding. "WHAT ARE YOU DOING?!"

Len blushed furiously. Neru glared at me.

"Um…kissing?" he asked.

"NO! JUST, NO!" I screamed. So much anger was bubbling inside me because of how much Len was hurting her best friend. I just had to let it all out.

"So…I'm NOT kissing?" Len asked, confused.

"UGH! YOU'RE SUCH AN IDIOT! CAN'T YOU SEE WHAT YOU'RE DOING TO RIN? YOU DON'T CARE ABOUT ANYONE BUT YOURSELF, HUH?!" I couldn't keep all the anger inside of me. I reached over and slapped Len in the face.

"OW!" Len cried. "What was that for?"

That was it. Here comes another Miku slap.

"Miku, stop hurting my boyfriend," Neru squeaked. Ugh. Another "Innocent Neru" act. It was sickening.

"WHAT was that for?! You MUST be kidding me!" I screeched. "You're so horrible. What is HAPPENING to you?!" With that, I stormed off.

You know what the worst part of all that was?

I think they started kissing again.

**-Rin's POV-**

Len didn't even look back at me…? He didn't try to save me? This wasn't the Len I knew. This wasn't the Len I knew at all.

He's been transformed.

More tears rolled down my red hot cheeks. What was it about Neru that made her so great that Len totally ignored me?

I had no idea.

My stomach tightened. I slowly opened my heavy eyelids to stare at the ceiling. It was so dull…just like my life.

It was dull and plain anyways. Why did I even care if it all just went away?

I sniffed. My heart was a hollow shell…

…because I had heard the conversation between my best friend and my worst enemies.


	5. One Last Heart

** Hey guys!**

** Okay, I think this is going to be the last chapter. I know I promised some of my friends that it would be longer, but I'm a poop who can't think of anymore ideas. This last part has been stuck in my head for the longest time anyways, so…yeah I just needed to put it XD**

** Enjoy!**

** Oh! I almost forgot! (Lol, no I didn't :P)**

** I'm dedicating this chapter to my friend's lizzie-rivers, mitchkat1, and rilenchan3700. I would also like to dedicate it to safi-ry, but she likes Neru and I made her mean…sorry safi-chan!**

** Anyways, here's the last chapter. ENJOY!**

**-Rin POV-**

"M-Miku, L-Luka…" I tried to call. A shearing pain had shot through my side, giving me a loss for words. I gasped in pain as another bolt of pain shot through me, making my heavy eyelids flash open.

"Rin?" I heard a voice call. _Thank goodness…I felt like I was going to die._

Miku rushed in my room, followed by Luka. "What's wrong?!" They cried at the same time.

"M-my sides…" Another shearing pain struck me, followed by a sharp scream.

"CALL 911!" Luka screamed to Miku, who nodded and ran as fast as she could down the stairs. I felt tears rolling down my cheeks as I panted. What was happening to me?

**-Len POV-**

Ugh. What in the world was all of that screaming? It was wrecking my special time with Neru. The nerve of some people.

All of a sudden, Miku ran into the room, grabbing the phone just as we were about to kiss.

"What the heck, Miku?" I asked, angrily.

Miku didn't even answer me. There were tears in her blue eyes as she quickly dialed a number.

"Hello? Yes, I need an ambulance at the Vocaloid Mansion, RIGHT AWAY!" She cried, trying to keep calm, but it wasn't working.

"Wait…ambulance?" I asked, my stomach tightening. _What was happening?!_

"YES AMBULENCE!" Miku screamed, losing her cool and bursting out in tears. She ran upstairs, wiping her eyes and crying, "Rin, WHY?!"

_Wait again…RIN?!_

Neru looked at me. "You don't really care about her, do you-"

I glared at Neru. "You," I growled.

She stared at me with worried eyes. They were so fake, and I realized that now. "W-What?"

"SHE WAS MY BEST FRIEND!" I cried. "YOU RUINED MY LIFE! HOW COULD YOU MAKE ME DO THIS TO RIN?!" I screeched.

"W-Wait-"

"No. Leave. NOW." I pointed to the door.

Neru ran out the door, crying. What a sick person…

I ran upstairs, my heart thumping as I saw people running in the door. They were carrying lots of medical materials and a stretcher, running upstairs. I followed them.

I turned to Miku, why was crying her eyes out. Even Luka, so calm, was sniffing and wiping away her tears.

Then I saw her.

Rin, so helpless on the stretcher. Her pale skin and bright red cheeks, her blue eyes, scared and in pain. She looked at me before closing her eyes again.

I ran outside and into the ambulance with Miku and Luka as Rin was being carried in. I sat by her bed, feeling tears pouring from my eyes.

What have I done…?

**time skip**

Finally, her eyes opened. I was sitting next to her bed, tears in my eyes.

A heart monitor was beeping next to her, a soft rhythm echoing off of the walls in the room.

"Rin…" I was at a loss for words. I couldn't even explain how horrible I felt for wrecking her life.

"I-It's okay," Rin croaked weakly, smiling a bit. How could she even smile?! I felt so horrible…I was the worst friend ever.

"No, it's NOT okay!" I cried, my voice shaking. "I've ruined your whole life! Everything is all my fault, and I'm so sorry…"

A weak hand rested on mine. I looked up at Rin.

"You haven't ruined my life. You're here with me now…" Rin's sweet voice was barely a whisper. It was so sweet…so caring…

…so helpless.

I looked outside to see Miku and Luka crying their eyes out into each other as a doctor told them some news. I saw Luka look at me with sad eyes. What had he told them?

Soon, the doctor came in. Rin was still looking at me.

"I'm afraid your friend here has had a serious illness, caused by lots of stress and by having the flu. Medicine should've helped to cure it."

I gulped, my eyes widening. Because of me, she had gotten out of taking the medicine.

"I'm very sorry," the doctor said before leaving. _Did this mean…_

_ Rin was going to DIE?_

My breath became shaky as I stared at the heart monitor. The beeping was getting slower and slower.

"NO! RIN! Y-YOU C-CAN'T DIE!" I cried, large amounts of tears bubbling up in my eyes.

Rin smiled at me. "It's okay. Because of you, my life is complete. It's okay if I die now."

A tear fell down my cheek. "R-Rin, I…I've always l-loved you, forever…b-but I didn't think y-you did too…" My voice was shaking louder and louder as I tried to push back tears. "A-And that's why I started g-going out with Neru…b-but it was a mistake…s-she made me not care about y-you anymore, w-which was the w-worst mistake of my life…" My stomach clenched so tightly I didn't think I could breathe.

"Len…I love you too," Rin croaked. Tears started to fall down her cheeks as her eyes started to close.

"RIN! NO! OPEN YOUR EYES RIGHT NOW! YOU CAN'T DIE! NO!" I screeched.

Beep…beep…beep…..beep…

I gasped, almost choking as the heart monitor stopped beeping. Rin's hand was still placed on top of mine…

…but it was cold…

I stared at her sweet angelic face…

…and cried…


End file.
